Apatosaurus
Apatosaurus ,including the popular, but obsolete synonym Brontosaurus, is a genus of sauropod dinosaur that lived about 150 million years ago, during the Jurassic Period (Kimmeridgian and Tithonian ages). It was one of the largest land animals that ever existed, with an average length of 23 meters (75 ft) and a mass of at least 23 metric tons (25 short tons). The name Apatosaurus means 'deceptive lizard', so-given because the chevron bones were similar to those of a prehistoric marine lizard, Mosasaurus. The cervical vertebrae were less elongated and more heavily constructed than those of Diplodocus and the bones of the leg were much stockier (despite being longer), implying a more robust animal. The tail was held above the ground during normal locomotion. Like most sauropods, Apatosaurus had only a single large claw on each forelimb, with the first three toes on the hind limb possessing claws. Fossils of this animal have been found in Nine Mile Quarry and Bone Cabin Quarry in Wyoming and at sites in Colorado, Oklahoma and Utah, USA. Description Apatosaurus was a tremendously large long-necked quadrupedal animal with a long whip-like tail. Its forelimbs were slightly longer than its hindlimbs. One measurement places the total length of Apatosaurus at 26 meters (85 ft) and its weight at 24-32 tons, roughly the weight of four elephants. The skull was small in comparison with the size of the animal. The jaws were lined with spatulate teeth, which resembled chisels, suited to an herbivorous diet. Classification and Naming Apatosaurus is a member of the family Diplodocidae, a clade of gigantic sauropod dinosaurs. The family includes some of the longest creatures ever to walk the earth, including Diplodocus, Supersaurus, Suuwassea, and Barosaurus. Within the subfamily Apatosaurinae, Apatosaurus may be most closely related to Suuwassea, Supersaurus and Eobrontosaurus. In 1877, Othniel Charles Marsh published the name of the type species Apatosaurus ajax. He followed this in 1879 with a description of another, more complete specimen, which he thought represented a new genus and named Brontosaurus excelsus. In 1903, Elmer Riggs pointed out that Brontosaurus excelsus was in fact so similar to Apatosaurus ajax that it belonged in the same genus, and which Riggs re-classified as Apatosaurus excelsus. According to the rules of the ICZN (which governs the scientific names of animals), the name Apatosaurus, having been published first, had priority as the official name; Brontosaurus was a junior synonym and therefore discarded from formal use. Apatosaurus ajax is the type species of the genus, and was named by the paleontologist Othniel Charles Marsh in 1877 after Ajax, the hero from Greek mythology. It is the holotype for the genus and two partial skeletons have been found, including part of a skull. Apatosaurus excelsus (originally Brontosaurus) was named by Marsh in 1879. It is known from six partial skeletons, including part of a skull, which have been found in the United States, in Colorado, Oklahoma, Utah, and Wyoming. Apatosaurus louisae was named by William Holland in 1915 in honor of Mrs. Louise Carnegie, wife of Andrew Carnegie who funded field research to find complete dinosaur skeletons in the American West. Apatosaurus louisae is known from one partial skeleton which was found in Colorado in the United States. Apatosaurus parvus was originally known as Elosaurus parvus, but was reclassified as a species of Apatosaurus in 1994. This synonymy was upheld in 2004. Robert T. Bakker made A. yahnahpin the type species of a new genus, Eobrontosaurus in 1998, so it is now properly Eobrontosaurus yahnahpin. It was named by Filla, James and Redman in 1994. One partial skeleton has been found in Wyoming. However, recently it has been argued that Eobrontosaurus belongs within Camarasaurus. Discovery Othniel Charles Marsh, a Professor of Paleontology at Yale University, described and named an incomplete (and juvenile) skeleton of Apatosaurus ajax in 1877. Two years later, Marsh announced the discovery of a larger and more complete specimen at Como Bluff Wyoming—which, because of discrepancies including the size difference, Marsh incorrectly identified as belonging to an entirely new genus and species. He dubbed the new species Brontosaurus excelsus, meaning "thunder lizard". In Popular Culture The length of time taken for Marsh's misclassification to be brought to public notice meant that the name Brontosaurus, associated as it was with one of the largest dinosaurs, became so famous that it persisted long after the name had officially been abandoned in scientific use. The terms brontosaurus, brontosaurs, and brontosaurians (no capital 'B'; no italics) are often used to refer generically to any of the sauropod dinosaurs. As late as 1989, the U.S. Post Office issued four "dinosaur" stamps, Tyrannosaurus Rex, Stegosaurus, "Pteradon" (misspelling of Pteranodon, which is a pterosaur and not a dinosaur) and Brontosaurus. The inclusion of these last two led to complaints of "fostering scientific illiteracy." The Post Office defended itself (in Postal Bulletin 21744) thus: Although now recognized by the scientific community as Apatosaurus, the name "Brontosaurus" was used for the stamp because it is more familiar to the general population. Stephen Jay Gould supported this position in his essay "Bully for Brontosaurus", though he echoed Riggs' original argument that "Brontosaurus" is a synonym for "Apatosaurus". Nevertheless, he noted that the creature has developed and continues to maintain an independent existence in the popular imagination. Since the beginning of film history, Brontosaurus has been depicted in cinema; the 1925 silent film The Lost World featured, using special effects by Willis O'Brien, a battle between a Brontosaurus and an Allosaurus. King Kong (1933) featured a Brontosaurus, as did the 2005 remake, described using the fictional scientific name "Brontosaurus baxteri", or Baxter's Thunder-Lizard, after a character in the film. The brontosaur of the 2005 film is noticeably different from the modern view of Apatosaurus, with a square head, low-hanging tail, and snake-like neck reminiscent of 1930s period depictions of the species in art. Also, the animated movie The Land Before Time and its sequels feature an Apatosaurus called Littlefoot and his family. When George Lucas made his special edition of Star Wars Episode IV: A New Hope in 1997, he added some large, long-necked animals based on the Brachiosaurus digital model from Jurassic Park. At an early stage he altered the CG department's suggested name 'Bronto,' taken from 'Brontosaurus,' to 'Ronto'. Category:Animals Category:Dinosaurs Category:Jurassic Fauna Category:Reptiles Category:Jurassic Reptiles